host.appear

Wraps the hosting controller lifecycle SwiftUI creates for you. One reading each time a SwiftUI screen finishes appearing, naming its own root view type.


Delivery	stream, onChange
Mechanism	swizzle
Requires	iOS 17+, basset 0.1.1+

Real output from basset request get, captured against a running app:

CAPTURED                  ELAPSED  INSTRUMENT

launch 12370866988505777912
2026-08-23T15:05:42.680Z  +0.0s    swiftui.host.appear(swiftUIHost)
├─ hostKind               hostingController
├─ hostRootViewType       ProvocationsView
├─ hostRootViewOpaque     false
├─ viewControllerClass    UIHostingController<ProvocationsView>
├─ hostAppearNanoseconds  545825417
├─ instanceId             1
└─ hostCount              1

Getting Started

SDK

CLI

Instruments

Reference